About one-third of kidney failure patients are not eligible have a transplant even if they have a donor with an otherwise perfectly matched tissue and blood type.

These patients have anti-donor antibody levels that are so high that any transplanted organ would be rejected by their highly sensitized immune system.

Now there is a specialized type of anti-rejection therapy using intravenous immunoglobulin (IVIG), which injects antibodies from healthy people into the blood supply, to modulate the immune system without suppressing it.

This makes kidney transplant possible for as much as 25 percent to 30 percent of this group of patients, who would otherwise not be eligible for a transplant because of their high antibody levels. The therapy was first adapted for use in transplant procedures by researchers at Cedars-Sinai hospital in Los Angeles.

Intravenous immunoglobulin therapy has been used for decades to treat immune system disorders. Immuniglobulins are proteins naturally produced by the body to help fight off invading organisms and infections. IVIG is a processed form of imminoglobulin and is made from blood plazma. IVIG is injected into a vein to add helpful antibodies to a patients blood stream. For the most highly sensitized patients, IVIG is combined with a new drug, Rituxan, which reduces treatment time from four months to one before transplantation. The therapy can be used in both living-donor and cadaver-donor transplants.

IVIG therapy is given during two dialysis treatments before transplant surgery. About two weeks after the first treatment with IVIG, Rituxan is given as an intravenous infusion. About two weeks after transplant, a final treatment with IVIG is given. Infusion of IVIG and Rituxan is associated with few side effects; the most common complaint is headache

Tissue compatibility is an issue for all patients receiving transplants, but in some cases heightened sensitivity complicates the bodies ability to receive a transplant. Rejection risks are much higher for those with high exposure to human leukocyte antigens (HLAs) that are not produced by their own bodies.

Exposure may be the result of blood transfusions, previous transplantation, or even pregnancy if the mother is exposed to the father's antigens, which are then expressed in the cells of the developing fetus.

The immune system is then "sensitized" to those antigens -- primed with antibodies that attack any foreign tissue, even if the antigens arrive in the form of a life-saving donated organ. About 40 percent of the patients who come to Cedars-Sinai for a kidney transplant are highly sensitized. According to researchers, between 95 percent and 97 percent can be successfully desensitized with IVIG and Rituxan.

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